This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 9 |
| 5 | 21 |
| 6 | 51 |
| 7 | 126 |
| 8 | 316 |
| 9 | 800 |
| 10 | 2040 |
| 11 | 5230 |
| 12 | 13464 |
| 13 | 34773 |
| 14 | 90035 |
| 15 | 233590 |
| 16 | 607011 |
| 17 | 1579438 |
| 18 | 4114014 |
| 19 | 10725109 |
| 20 | 27979704 |
| 21 | 73035818 |
| 22 | 190737623 |
| 23 | 498320800 |
| 24 | 1302341411 |
| 25 | 3404552915 |
| 26 | 8902154847 |
| 27 | 23281653957 |
| 28 | 60897957049 |
| 29 | 159312797657 |